The predominant mass storage device in conventional computing devices is the hard disk drive. Hard disk drives are relatively large, electromechanical devices that can store a relatively large amount of data. The stored data is accessed through a read/write head that rides on a cushion of air above the rapidly rotating disk. The read/write head moves radially to access data in different tracks of the rotating disk. Data transfer is limited by the speed at which the disc rotates and the speed with which the read/write head is positioned over the required track. Even with the fastest devices, access times are on the order of thousands of microseconds, due to the relatively large mechanical motions and inertia involved. This time scale is at least seven orders of magnitude slower than the sub-nanosecond time scales at which processors operate. The discrepancy may leave the processor starved for data. Compact Disc and DVD storage systems, also limited by the speed at which a disc rotates and the speed with which a read/write head is positioned over a required track, are associated with similar discrepancies.
During the time the processor is starved for data, either valuable computing time is lost or the processor must perform another task, which also may lead to data starvation. Such data starved conditions are referred to in the art as being input/output (I/O) bound or bottlenecked.